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Regular Expressions

L1

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RegEx1.js
#!/usr/bin/env node;
const Utils = require('./Utils');

const main = async () => {
	const s = "Four score and seven years ago...";
	console.log("Match 1: " + Utils.defined(s.match(/s.*e/)));
	console.log("Match 2: " + Utils.defined(s.match(/\bs.*e\b/)));
	console.log("Match 3: " + Utils.defined(s.match(/s...e/)));
	console.log("Match 4: " + Utils.defined(s.match(/b.d/)));

	let subgroups = Utils.match(/(\w+)\s*(\w+)/, s);
	console.log("Find First (with subgroups): " + Utils.listToString(subgroups));
	subgroups = Utils.match(/bad match/, s);
	console.log("Find First (bad match): " + Utils.listToString(subgroups));

	let matches = Utils.match(/\w+/g, s);
	console.log("Find All: (matches only)" + Utils.listToString(matches));
	matches = Utils.match(/bad match/g, s);
	console.log("Find All (bad match): " + Utils.listToString(matches));
}
main().catch( e => { console.error(e) } );
Output
$ node RegEx1.js Match 1: true Match 2: true Match 3: true Match 4: false Find First (with subgroups): ["Four score", "Four", "score"] Find First (bad match): [] Find All: (matches only)["Four", "score", "and", "seven", "years", "ago"] Find All (bad match): []
RegEx2.js
#!/usr/bin/env node;
const Utils = require('./Utils');

const main = async () => {
	const s = "Four score and seven years ago...";
	console.log("Replace First 1: " + s.replace(/\.\.\./, "!!!"));
	console.log("Replace First 2: " + s.replace(/\b...\b/, "???"));
	console.log("Replace First 3: " + s.replace(/b.d/, "???"));
	console.log("Replace First 4: " + s.replace(/(\w+) (\w+)/, "$2 $1"));

	console.log("Replace All 1: " + s.replaceAll(/\b...\b/g, "???"));
	console.log("Replace All 2: " + s.replaceAll(/(\w+) (\w+)/g, "$2 $1"));
}
main().catch( e => { console.error(e) } );
Output
$ node RegEx2.js Replace First 1: Four score and seven years ago!!! Replace First 2: Four score ??? seven years ago... Replace First 3: Four score and seven years ago... Replace First 4: score Four and seven years ago... Replace All 1: Four score ??? seven years ???... Replace All 2: score Four seven and ago years...
RegEx3.js
#!/usr/bin/env node;
const Utils = require('./Utils');

const main = async () => {
	const str = "Four score and seven years ago...";
	console.log("Split 1: " + Utils.listToString(str.split(/ /)));
	console.log("Split 2: " + Utils.listToString(str.split(/[eo]/)));
	console.log("Split 3: " + Utils.listToString(str.split(/\s/)));
	console.log("Split 4: " + Utils.listToString(str.split(/\W/)));
}
main().catch( e => { console.error(e) } );
Output
$ node RegEx3.js Split 1: ["Four", "score", "and", "seven", "years", "ago..."] Split 2: ["F", "ur sc", "r", " and s", "v", "n y", "ars ag", "..."] Split 3: ["Four", "score", "and", "seven", "years", "ago..."] Split 4: ["Four", "score", "and", "seven", "years", "ago", "", "", ""]
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